Neuroendocrine System and Reproduction

A comprehensive set of vocabulary flashcards covering the neuroendocrine glands, hormonal control of sexual development, behavioral differences, and parental care based on the lecture transcript.

Neuroendocrine system

A system that effects slower changes in the body compared to the CNS via the release of hormones into the blood supply.

Hypothalamus

The brain structure responsible for the main control of hormones; it releases gonadotropin-releasing hormone ($GnRH$) to trigger the pituitary gland.

Anterior pituitary gland

Known as the master gland, it controls the endocrine system by secreting hormones that stimulate other glands under the direction of the hypothalamus.

Posterior pituitary gland

The gland that releases hormones produced in the hypothalamus and carried there in vesicles by means of axoplasmic transport.

Müllerian system

The embryonic precursor of the internal female reproductive system, which develops into the fimbriae, fallopian tubes, uterus, and inner vagina.

Wolffian system

The embryonic precursor of the internal male reproductive system, which develops into the vas deferens, seminal vesicles, and prostate under the influence of testosterone.

Anti-Müllerian hormone

A peptide secreted by the fetal testes that causes the Müllerian system to wither away, a process called defeminization.

Androgens

A class of steroid hormones, such as testosterone, that promote the development of male characteristics (masculinization).

Dihydrotestosterone ($DHT$)

A hormone converted from testosterone that is responsible for the differentiation and development of typical male external genitalia.

Aromatization

The chemical process that converts testosterone into estradiol; in some species, this process is responsible for the masculinizing of the brain.

Medial Preoptic Area ($MPA$)

A sexually dimorphic region of the hypothalamus that is larger in males; it is critical for male sexual behavior and maternal behavior.

Organisational effects

Hormonal influences that occur during a critical period of development (such as prenatally) to permanently alter the body or brain structure.

Activational effects

The effects of hormones that occur later in life (e.g., at puberty) to trigger specific behaviors or physiological responses in previously organized tissues.

Androgen insensitivity syndrome

A condition in $XY$ individuals who lack functioning androgen receptors; they develop external female features but have no internal reproductive organs.

Turner’s syndrome

A genetic disorder caused by an $XO$ chromosome configuration resulting in the absence of ovaries or testes, though the individual develops internal and external female sex organs.

Persistent Müllerian duct syndrome

A condition in $XY$ males caused by a failure to produce anti-Müllerian hormone or its receptors, leading to the development of both male and female internal sex organs.

$5\alpha$-reductase deficiency

An enzyme deficiency that impairs the differentiation of male external genitalia, often resulting in the formation of a penis only at the onset of puberty.

Sexually Dimorphic Nuclei ($SDN$)

Groups of neurons in the preoptic area that differ in size between males and females; lesions in this area decrease masculine sexual behavior.

$2M$ females

Female mouse fetuses that were positioned between two males in the uterus; they are exposed to higher levels of testosterone and display more inter-female aggressiveness.

Pheromones

Chemicals released by one animal that affect the behavior or physiology of another member of the same species, such as synchronizing menstrual cycles.

Oxytocin

A hormone released by the pituitary gland that is responsible for the refractory period in males and plays a role in parent-infant bond formation and reinforcement.

Prolactin

A hormone that stimulates nest-building in females and is associated with stronger feelings of sympathy and activation in human fathers when hearing infant cries.

$V1a$ vasopressin receptors

Receptors found in higher levels in the ventral forebrain of monogamous prairie voles compared to polygamous meadow moles; they are linked to pair bonding.